Furnace roof



E. P. STEVENS FURNACE ROOF 5 Sheets-Shoe*I l Filed Dec.

Oct. 21, 1930. E. P. STEVENS 1,773,775

FURNACE ROOF Filed Dec. 2l, 1922 5 Sheets-Sheet 2 M -Ilii m lllll www. I 1.21 dlrlll 1R.--

Oct. 21,1530. E. P. STEVENS 1,778776 FURNACE ROOF Patented Oct. 21, 1930 l UNITED STATES PATENT OFFICE ENOCH P. STEVENS, OF MORGAN PARK, CHICAGO, ILLINOIS, ASSIGNOB'TO Am):

ARCH COMPANY, INC., A CORPORATION OF NEW YORK j .'F'UBN ACE ROOF Application le December 21, 1922. Serial No. 608,345.

My invention relates to furnace roof con-l struction and is especially concerned with malleable furnaces. One of my main objects is to overcome various difficulties and drawbacks of roof constructions heretofore em' v of the invention known to me.

In the drawings, Fig. 1 is a somewhat diagrammatic side view of a malleable furnace i with a roof conveniently embodying my invention, various parts being omitted to avoid confusion.

Fig. 2 is a corresponding fragmentary plan view.

Fig. 3 shows a fragmentary transverse section through the furnace, on a larger scale than Figs. 1 and 2, with various parts partly broken away or in section.

Figs. 4 and 5 show fragmentary transverse sections through the roof structure, on a larger scale than Figs. 1, 2 and 3.

Figs. 6 is a fragmentary view similar to Fig. 3, illustrating a modification.

In itself, the furnace illustrated in Figs. 1, 2 and 3 may be of the usual type and design for the production of malleable iron, so that general or detailed description is unnecessary. Referring, then, at once to the roof 10, it Wi ll be seen that while it resembles those lof malleable furnaces as heretofore constructed in having a slightly cambered, arching form,

it is ,Hatter than usual; and instead of resting on the side walls 11 and exerting lateral thrust on them when it expands, as well as heavy downward pressure atY all times, it is externally supported, by an overlying framework or cradle structure 12. As shown, the

roof 10 is of sectional construction, compris-v ing a series of gnore or less unitary, independent transverse bungs or -arch units 14, 15 each composed of a row of arch fire brick. The ends of eachbung 14, 15 overlap the side walls of the furnace with slight clearance, and seals 16 of sand or the like are lprovided to prevent leakage of the hot gases through these overlap joints. Atthe ends of the furnace,

similar joints and seals exist between the i end bungs 14 and the end walls.

The cradle structure 12 for supporting the roof 10 is here shown as completely straddling the furnace, consisting of a series of uprights 17 along either side with their tops tied together by longitudinal stringers 18,` and suitable transverse members or cross beams 20 supported by the stringers. As shown in Figs. 1 and 3, the uprights 17 lwith the super# jacent parts are structurally quite independent of the furnace Walls,-having, indeed, the character of channel OLI-bar pillars or posts separated from the furnace sides, rather than that of buckstays. Hence the roof 10 not onlyU imposes no weight load on the furnace walls,-

but iscompletely free for independent expansion andcontra'ction without any lateral or other thrust on or reaction withthe walls. Each of the transverse girder membersv 20 is here shown as composed of a pair of angle bars facing flange to flange, with their ends resting on top of the I-shaped stringers 18. With the exception of .those for the roof bungs 15 that'must regularly be removed to `charge the furnace, the girders 20 may be suitably secured to the stringers 18, so as to brace and tie together the longtiudinal lateral supporting ystructures composed of these stringers and the uprights 17. Asshown in Fig. 3, the ends of the girders 20 project a little beyond the stringers 18, sol that when any of the roof bungs 14, 15 (eitherv the charging bungs or the others) are lifted olf, .one by one,-as by an overhead crane or the like,-they may be deposited and stored (so to speakon a sort of rack shown as composed of longitudinals 22 secured to the tops of extra high uprights 17 at either side of the furnace in position to receive the ends of the corresponding girders. r

As shown in Figs. 4 and 5, the refrac ry fire brick ofeach bung 14, 15 have T-s'haped that straddle the upper anges o the pair ofv angle bars forming each girder 20, and are secu-red to these clips by opposed nuts by means of which a certain measure of vertical adjustment may be made. Thus, it will be seen, the brick of each bung 14, 15 are free to expand and contract, and to shift their positions bodily lengthwise of their girder 20,- independently of one another, and without interfering reaction with other parts, or lateral thrusts on-the furnace or the lateral supports 17, 18. Also, all parts of the supporting structure are protected against overheating from the refractory roof bungs by their free exposure to the air, which permits dissipation of the heat received by conduction and radiation, etc. y

In order that the joints between the brick of each bung 14, 15 may be kept tightly closed under all conditions, despite expansion and contraction, provision may preferably be made for exerting ayielding pressure on the bung ends. As here shown, means for doing this are carried by each girder 20, comprising (see Fig. 3) a compression spring 30 that acts on a longitudinally movable rod member 31 having a pin and slot-connection 32 with the upper arm of a lever 33 whose lower arm is pivotally connected to a shoe or backing plate 34 that ybears against the outermost bung brick, and has a lbottom lip 35 that takes I under and protects the lower outer corner of the brick. As here shown, the lever 33 is fulcrumed and reacts on a double bracket 36 depending from the girder 20, and the rod 31 is mounted and guided in bracket pieces 37 secured between the upright flanges o f the angle bars that form the member 20, and connecting them together. The spring 30 mounted on each end of each girder acts between the outer bracket 37 and an adjustable abutment 38 on the outer end of the rod 31, urging the upper arm of the lever 33 outward and pressing the lower arm inward on the bung end. Thus, it will be seen, the bung as be seen that the refractory transverse bungs 14, 15 are of wedge-like cross section (i. e., the outside faces or edges of the bung brick are inclined relatively to one another),and expand upward and downward in alternation throughout the length of the furnace. This conformation allows the bungs 14, 15 to be perfectly close-fitting andv tight with one another when in place, yet affords clearance and pairs of contiguous bungs 15 are vertical.l

This, it will be seen, permits such bungs 15 to be lifted olf concurrently in convenient agroupments: i. e. continuous sections of the roof 10 composed of these bun s 15 can be lifted of in their entirety. As s own inrFig. 5, the girders 20 belonging to pairs ofthe bungs 15 with vertical juxtaposed faces are secured together by underlying plates 40, to facilitate their removal as unitary sections. y In the modified bung unit construction illustrated in Fig. 6, the ends of the girders 20 are provided with feet 44 to rest on the lateral supporting structures, which have angle bars 45 with upstanfiin anges along their tops to hold the feet mp ace. Only one guide and connecting bracket 37 is provided at each end of the :girder 20. The lever 33 is fulcrumed and reacts on the foot 44 at 46,

and its upper arm is bent to allow the rod 31 to be made shorter. The member 48 against which the spring 30 abuts at the outer end of therod 31 also serves for the pin and slot connection 32 between rod 31 and lever 33.

As a means of dispensing with merely repetitive description, various parts and features of Fig. 6 corresponding to those of Figs. 1 to 5 are marked with the same reference characters as in Figs. 1 to 5.

What I claim is:.

1. A furnace roof bung unit comprislng a girder adapted to be spanned between supports at the furnace side walls; a bung of refractory bricks with the bricks freely suspended from -the girder; and yielding means carried by said girder for exerting pressure on the bung ends to compensate for expansion and contraction of the bricks and maintain tight joints between them.

2. A furnace roof bung unit comprising a girder for spanning the furnace; a bung'of refractory bricks with longitudinal supporting runners sustainingly engaging their upper `portions and freely suspended from said girder at intervals; and means carried by said girder for exerting pressure on the bung ends to close the joints between the bung brick.

3. A furnace roof bung unit comprisin a. transverse girder adapted to be spanned ietween supportsoutside of the furnace side walls; a bung of refractory bricks with longitudinal supporting runners sustainingly engaging their upper portions, and hangers at intervals for suspending said runners from said girder, so that the brick may shift and adjust themselves freely for expansion and contraction; and means for closing the joints between the bung brick comprising springs mounted on the ends of said girder and levers with their upper arms urged outward by said springs and their lower arms pressing inward on the bung ends.

4. A furnace roof bung unit comprising a girder with feet at its ends for supporting it; a bung of refractory brick suspended from and below said girder between its said feet with freedom for vertical adjustment; and resilient means for closing the joints between the bung brick reacting at least in part between said feet and the bung ends.

5. A furnace roof bung unit comprising a girder with feet at its ends for supporting it; a bung of refractory bricks sus ended from and below said girder between its said feet with freedom for adjustment longitudi-V nally and vertically with reference to the girder; and means carried by said girder for closing the joints between said brick,`com prising springs mounted on the girder, and levers with their upper arms urged outward by said springs and'their lower arms pressing inward on the bung ends.

In testimony whereof, I have hereunto signed my name.

ENOCH P. STEVENS. 

